JP2016068306A - Reaction liquid and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a reaction liquid composition having excellent recovery property from clogging and capable of obtaining a recorded material with a high quality image and suppressing curling of a recording medium; and a recording method using the same.SOLUTION: There is provided a reaction liquid which comprises water, a flocculant for flocculating a component of an ink composition and a betaine compound having a molecular weight of 100 to 200 and is used by adhering to a recording medium in a recording method in which the ink composition is adhered to the recording method by an inkjet method.SELECTED DRAWING: None

Description

  The present invention relates to a reaction solution and a recording method.

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been made on the image of the recorded matter to be obtained. For example, Patent Document 1 discloses that even if the image quality improvement processing liquid is extremely ionic, a very small amount of image quality improvement processing liquid can be applied to the medium, and a remarkable image quality improvement processing performance can be obtained. For the purpose of providing an image quality improvement treatment liquid that can prevent ink bleeding on a medium while suppressing consumption, and that can form an image with excellent cost performance, an ionic coloring material or water in water and water An image quality improvement treatment liquid that improves the image quality of ink on the medium by contacting with the ink containing the ionic color material by the adsorption of the ionic member and reacting with the color material in the ink to agglomerate An image quality improving treatment liquid comprising a cationic member or a member that acidifies water, a nonionic surfactant or an amphoteric surfactant as a foaming agent, and a water-insoluble fatty acid that is insoluble in water is disclosed. Is There.

Japanese Patent No. 5152650

  However, when a treatment liquid is used separately from the ink composition, there is a problem in that the amount of moisture applied to the recording medium increases, which makes the recording medium easily curled. In addition, when a treatment liquid as described in Patent Document 1 is applied to a recording medium by an ink jet method, the nozzle is likely to be clogged, and in addition, even if the clogging is cleaned, the clogging is long. In addition, there is a problem that short-term recoverability is low.

  The present invention has been made in order to solve at least a part of the above-described problems, and can obtain a high-quality recorded material, and can suppress curling of a recording medium, and can recover from clogging. It is another object of the present invention to provide a reaction liquid composition part which is excellent in the recording medium and a recording method using the same.

  The present inventors diligently studied to solve the above problems. As a result, the present inventors have found that the above problem can be solved if the reaction solution uses a predetermined compound, and the present invention has been completed.

That is, the present invention is as follows.
[1]
Water, a flocculant for aggregating the components of the ink composition, and a betaine compound having a molecular weight of 100 to 200,
In the recording method in which the ink composition is attached to a recording medium by an ink jet method, the recording medium is used by being attached to the recording medium.
Reaction liquid.
[2]
The reaction solution according to [1], wherein the betaine compound content is 2.0 to 20% by mass.
[3]
The reaction solution according to [1] or [2] above, wherein the betaine compound contains a betaine compound having a trimethylamino group.
[4]
The reaction according to any one of [1] to [3], wherein the flocculant contains at least one selected from the group consisting of a polyvalent metal salt, an organic acid, an organic acid salt, and a cationic polymer. liquid.
[5]
Including polyhydric alcohols having a boiling point of 280 ° C. or higher,
The reaction solution according to any one of [1] to [4], wherein the content of the polyhydric alcohol is 2.0% by mass or less.
[6]
6. The reaction liquid according to any one of [1] to [5], which is used in the recording method in which the recording medium is an absorbent recording medium.
[7]
Furthermore, the reaction liquid according to item [6], which is also used in the recording method in which the recording medium is a low-absorbency recording medium or a non-absorbing recording medium.
[8]
The reaction liquid according to any one of [1] to [7], wherein the ink composition contains a betaine compound having a molecular weight of 100 to 200.
[9]
The reaction solution according to any one of [1] to [8], which is attached to the recording medium by an ink jet method.
[10]
[1] to [1] to [1] to [1], wherein an inkjet head having a nozzle for discharging the reaction liquid is attached to the recording medium by an inkjet method while being scanned relatively once with respect to the recording medium. [9] The reaction solution according to any one of [9].
[11]
The reaction solution according to any one of [1] to [10], wherein the amount of the flocculant attached to the recording medium is 0.010 to 2.0 g / m ² .
[12]
A reaction liquid attaching step of forming the first recording area by attaching the reaction liquid according to any one of [1] to [11] above to the recording medium;
An ink composition attaching step of attaching an ink composition to at least a part of the first recording area to form a second recording area,
Recording method.

  Hereinafter, the embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. However, the present invention is not limited to this, and various modifications are possible without departing from the scope of the present invention. It is.

(Reaction solution)
The reaction liquid of this embodiment includes water, an aggregating agent that aggregates the components of the ink composition, and a betaine compound having a molecular weight of 100 to 200, and adheres the ink composition to a recording medium by an inkjet method. In the recording method, the recording medium is used by being attached to the recording medium.

  The method for attaching the reaction liquid to the recording medium is not particularly limited, and for example, roller coating, spray coating, and ink jet coating can be used. Among these, it is preferable to attach the reaction liquid to the recording medium by an ink jet method. By including a betaine compound having a molecular weight of 100 to 200, the viscosity of the reaction solution is lowered, so that even when the reaction solution is attached to a recording medium by the ink jet method, the clogging recovery property of the nozzle is further improved. Therefore, if it is the reaction liquid of this embodiment, it can be used suitably as a reaction liquid for an inkjet method, and by this, it can adhere selectively only to a required part, Therefore The amount of liquid used, ie, printing cost, Advantages of the inkjet method such as reduction and shortening of drying time can be enjoyed.

  Further, it is preferable to apply the reaction liquid to a recording medium by an ink jet method using a line head. This is more preferable because it tends to be superior by improving dot landing accuracy and shortening the printing time.

The reaction liquid of the present embodiment is preferably one that adheres to the recording medium with a predetermined adhesion amount. Specifically, the adhesion amount of the reaction liquid to the recording medium is preferably 2.0 to 10 g / m ² , preferably 2.5 to 8.5 g / m ² , preferably 3.5. it is a ~6.5g / m ^2. When the amount of the reaction solution adhered is 2.0 g / m ² or more, the image quality of the obtained recorded matter tends to be further improved. In addition, curling tends to be further suppressed when the amount of the reaction solution deposited is 10 g / m ² or less.

  The reaction liquid of the present embodiment is attached to a recording medium by an ink jet method while an inkjet head having a nozzle for discharging the reaction liquid is scanned only once relative to the recording medium. Is preferred. That is, it is preferable that the reaction liquid of this embodiment is a reaction liquid for 1-pass printing inkjet methods. One-pass printing, in which all dots are attached in one pass, has the advantage of generally higher recording speed than multi-pass printing in which dots of adjacent pixels are attached in separate passes. If the same, the one-pass printing tends to increase the amount of ink applied per unit area compared to the multi-pass, and therefore, the amount of water applied to the recording medium is also relatively large. , Tend to curl easily. Therefore, the present invention is particularly useful in the one-pass printing ink jet method. Further, when all the reaction liquids used for recording are attached at one time in one pass, the degree of curling that occurs at the time of attachment may be deteriorated, and the present invention is particularly useful in this respect as well.

  The reaction liquid of the present embodiment is a residual volatile amount with respect to the mass of the volatile component contained in the reaction liquid attached to the recording medium at the time when the ink composition is attached (it remains on the recording medium without being volatilized. It is preferable that the resin is used under the condition that the mass% of the amount is within a predetermined range. Specifically, the volatile residual amount of the volatile component is preferably 5% by mass or more, more preferably 10% by mass or more, with respect to the total amount of the volatile components contained in the reaction solution before adhesion, More preferably, it is 20 mass% or more, More preferably, it is 50 mass% or more, More preferably, it is 70 mass% or more, Most preferably, it is 80 mass% or more. The upper limit of the volatile residual amount is 100% by mass or less, and is not limited, but is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 90% by mass or less. On the other hand, when the remaining amount of volatilization is reduced, the upper limit is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less. When the remaining amount of volatilization is larger, for example, 50% by mass or more, the recording speed is further improved, but the amount of moisture on the recording medium increases, so that curling is more likely to occur. In this respect, by using the reaction liquid of the present embodiment, it is possible to improve the recording speed while suppressing the occurrence of curling. In addition, when the remaining amount of volatilization is less, for example, 95% by mass or less, bleeding tends to be further suppressed, and even when curl generation is increased due to rapid drying when the reaction solution is dried, By using the reaction solution, curling can be suppressed. Here, the “reaction liquid before adhering” means a state before adhering the reaction liquid adhering to the recording medium in the reaction liquid adhering step.

  In addition, the reaction liquid of the present embodiment is preferably used for a recording method that does not include a step of heating and drying the reaction liquid. When there is no step of heating and drying the reaction solution, the recording speed is further improved, but the amount of water on the recording medium increases, so that curling is more likely to occur. In this respect, by using the reaction liquid of the present embodiment, it is possible to improve the recording speed while suppressing the occurrence of curling. On the other hand, you may use for the recording method which has the process of heat-drying a reaction liquid. By using the reaction liquid of this embodiment, it becomes possible to suppress the occurrence of curling due to rapid drying.

〔water〕
Examples of water include water from which ionic impurities have been removed as much as possible, such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water, and ultrapure water. In addition, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, generation of mold and bacteria can be prevented when the ink is stored for a long period of time. This tends to improve the storage stability.

  The content of water is preferably 20 to 55% by mass, more preferably 25 to 50% by mass, and still more preferably 30 to 45% by mass with respect to the total amount of the reaction solution. When the water content is within the above range, the clogging recovery property is further improved and curling tends to be further suppressed.

[Flocculant]
The aggregating agent in the reaction liquid interacts with the ink composition, thereby aggregating the components of the ink composition adhering to the recording medium by the ink jet method to thicken or insolubilize the ink composition. Thereby, landing interference and bleeding of the ink composition to be subsequently attached can be prevented, and lines and fine images can be drawn uniformly. Therefore, by using the reaction liquid of this embodiment, a recorded product with higher image quality can be obtained.

  Although it does not specifically limit as an aggregating agent, For example, at least 1 sort (s) chosen from the group which consists of a polyvalent metal salt, an organic acid, an organic acid salt, and a cationic polymer is mentioned. Among these, at least one selected from the group consisting of polyvalent metal salts, organic acid salts, and cationic polymers is preferable, and at least one selected from the group consisting of polyvalent metal salts and cationic polymers is more preferable. By using such a flocculant, the image quality of the obtained recorded matter tends to be further improved. Examples of components contained in the ink composition that aggregates with the aggregating agent include pigments and resin fine particles described later.

(Polyvalent metal salt)
Although it does not specifically limit as a polyvalent metal salt, For example, the polyvalent metal salt of an inorganic acid or the polyvalent metal salt of an organic acid is preferable. Such a polyvalent metal salt is not particularly limited, but examples thereof include alkaline earth metals belonging to Group 2 of the periodic table (eg, magnesium, calcium), and transition metals belonging to Group 3 of the periodic table (eg, lanthanum). And salts of earth metals (eg, aluminum) and lanthanides (eg, neodymium) from group 13 of the periodic table. As these polyvalent metal salts, carboxylate (formate, acetate, benzoate, etc.), sulfate, nitrate, chloride, and thiocyanate are suitable. Among these, preferably, calcium salt or magnesium salt of carboxylic acid (formic acid, acetic acid, benzoate, etc.), calcium salt or magnesium salt of sulfuric acid, calcium salt or magnesium salt of nitric acid, calcium chloride, magnesium chloride, and thiocyanate. The calcium salt or magnesium salt of an acid is mentioned. In addition, a polyvalent metal salt may be used individually by 1 type, and may use 2 or more types together.

(Organic acid)
The organic acid is not particularly limited, and examples thereof include acetic acid, phosphoric acid, oxalic acid, malonic acid, and citric acid. Among these, monovalent or divalent or higher carboxylic acids are preferable. By including such a carboxylic acid, the aggregation effect of the resin fine particles (A) is further improved, and as a result, the color developability tends to be more excellent. In addition, an organic acid may be used individually by 1 type, and may use 2 or more types together.

(Organic acid salt)
Although it does not specifically limit as an organic acid salt, For example, the salt of the said organic acid is mentioned, The salt of a monovalent organic acid is preferable. The monovalent organic acid salt is not particularly limited, and examples thereof include formate, acetate, and benzoate. In addition, organic acid salt may be used individually by 1 type, and may use 2 or more types together.

(Cationic polymer)
Although it does not specifically limit as a cationic polymer, For example, the polymer which has a primary-tertiary amino group or a quaternary ammonium base as a cationic group is mentioned. Specifically, a homopolymer of a monomer (cationic monomer) having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base, or the cationic monomer and other monomers (hereinafter referred to as “monomers”) , "Non-cationic monomer") or a condensation polymer. The cationic polymer can be used in the form of either a water-soluble polymer or water-dispersible latex particles. In addition, a cationic polymer may be used individually by 1 type, and may use 2 or more types together.

  Although it does not specifically limit as a cationic monomer, For example, the vinyl compound which has a vinyl group, a primary-tertiary amino group and its salt, or a quaternary ammonium base; primary-tertiary amino (Meth) acrylate having a group and a salt thereof, or a quaternary ammonium base; (meth) acrylamide having a primary to tertiary amino group and a salt thereof, or a quaternary ammonium base.

  Among these, a vinyl compound having a vinyl group and a primary to tertiary amino group and a salt thereof or a quaternary ammonium base is preferable. Examples of such vinyl compounds include, but are not limited to, for example, allylamine, allylamine hydrochloride, allylamine acetate, allylamine sulfate, diallylamine, diallylamine hydrochloride, diallylamine acetate, diallylamine sulfate, diallylmethylamine and salts thereof ( Examples of the salt include hydrochloride, acetate, sulfate and the like, diallylethylamine and its salt (for example, hydrochloride, acetate, sulfate and the like), diallyldimethylammonium salt (of the salt). Examples of the counter anion include chloride and acetate ion sulfate ion. By using a cationic polymer having a constitutional unit composed of these monomers, the image quality of the obtained recorded matter tends to be further improved.

The cationic polymer that can be obtained from the above monomers is not particularly limited, and examples thereof include polydiallyldimethylammonium chloride, polymethacryloyloxyethyl-β-hydroxyethyldimethylammonium chloride, polyethyleneimine, polyallylamine and derivatives thereof, polyamide- Polyamine resin, cationized starch, dicyandiamide formalin condensate, dimethyl-2-hydroxypropylammonium salt polymer, polyamidine, polyvinylamine, dicyanamide-formalin polycondensate represented by dicyan-based chaotic resin, dicyanamide-diethylenetriamine polycondensate Representative polyamine-based chaotic resin, epichlorohydrin-dimethylamine addition polymer, dimethyldialin ammonium chloride -SO ₂ copolymer, diallylamine salt -SO ₂ copolymer, a quaternary ammonium base-substituted alkyl group having an ester moiety (meth) acrylate-containing polymers, styryl polymers having a quaternary ammonium base-substituted alkyl group Is mentioned. Among these, polyallylamine and epichlorohydrin-dimethylamine addition polymer are more preferable. By using such a cationic polymer, the image quality of the obtained recorded matter tends to be further improved.

Adhesion amount of the reaction solution of the aggregating agent is preferably 0.010 g / m ² or more 2.0 g / m ² or less, more preferably 0.020 g / m ² or more 1.6 g / m ² or less . When the adhesion amount of the coagulant in the reaction solution is 0.010 g / m ² or more, the color material and the resin component are more easily aggregated. Further, when the amount of the coagulant adhering to the reaction solution is 2.0 g / m ² or less, the drying time of the reaction solution can be shortened, so that the recording speed can be increased.

Furthermore, the adhesion amount of the flocculant in the reaction solution is more preferably 0.030 g / m ² or more in that the aggregation of the coloring material and the resin component is further excellent. In addition, the reaction solution has a longer drying time while ensuring the effect of aggregating the colorant and resin components, and the amount of the coagulant adhering to the reaction solution is reduced in terms of stickiness of the recorded matter and reduction of odor caused by the flocculant. Is preferably 1.0 g / m ² or less, more preferably 0.50 g / m ² or less, particularly preferably 0.20 g / m ² or less, and even more preferably 0.10 g / m ² or less.

[Betaine compound]
Curling occurs in the process of adhering a composition containing water such as a reaction liquid or an ink composition to a recording medium and drying. At this time, the curling of the recording medium can be suppressed by using the betaine compound.

  The molecular weight of a betaine compound is 100-200, Preferably it is 105-190, Preferably it is 110-170. When the molecular weight of the betaine compound is within the above range, the curl suppressing effect is further improved, and the clogging recovery property tends to be further improved due to the relatively low molecular weight. In addition, when the molecular weight of a betaine compound is over 200, the viscosity of a reaction liquid rises, and thereby clogging recoverability deteriorates.

  A betaine compound is a compound that has a positive charge and a negative charge at non-adjacent positions in the same molecule, and has no positively charged hydrogen atoms bonded to dissociable hydrogen atoms, so that the molecule as a whole has no charge. (Inner salt). Preferred betaine compounds are N-alkyl substituted amino acids, more preferably N-trialkyl substituted amino acids. Specific examples of the betaine compound are not particularly limited. For example, glycine betaine (molecular weight 117), γ-butyrobetaine (145), homarine (137), trigonelline (137), carnitine (161), homoserine Amino acids such as betaine (same as 161), valine betaine (same as 159), lysine betaine (same as 188), ornithine betaine (same as 176), alanine betaine (same as 117), stachydrin (same as 185), and betaine glutamate (same as 189) Examples include betaines that are N-trialkyl-substituted products. By including such a betaine compound, the curl suppression effect is further improved, and since the molecular weight is relatively low, an increase in the viscosity of the reaction solution can be suppressed, and the clogging recovery property tends to be further improved. .

  The content of the betaine compound is preferably 2.0 to 20% by mass, more preferably 2.0 to 15% by mass, and further preferably 4.0 to 15.0% with respect to the total amount of the reaction solution. % By mass. When the content of the betaine compound is 2.0% by mass or more, the curl suppressing effect tends to be further improved. Moreover, when the content of the betaine compound is 20% by mass or less, an increase in the viscosity of the reaction solution can be suppressed, and the clogging recovery property tends to be further improved.

  The reaction solution may contain other components as necessary. Although it does not specifically limit as another component, For example, an organic solvent, surfactant, etc. are mentioned.

(Organic solvent)
The organic solvent is not particularly limited. For example, hydrocarbon solvents such as toluene, hexane, cyclohexane, benzene, octane and isooctane; ester solvents such as ethyl acetate, butyl acetate and γ-butyrolactone; acetone, methyl ethyl ketone and methyl isobutyl Ketone solvents such as ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol, glycerin, propylene glycol, triethylene glycol and triethylene glycol monobutyl ether; halogen solvents such as dichloroethane and chloroform; diethyl ether Ether solvents such as tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N- Chill-2-pyrrolidone, 2-pyrrolidone, N- methyl -ε- caprolactam, amides hexamethylphosphoramide solvents; Other water soluble organic solvents.

  Among these, an alcohol solvent having a boiling point within the range of 180 to 230 ° C. at 1 atm is preferable. If the alcoholic solvent contained in the ink composition has a boiling point of less than 180 ° C. at 1 atm, the ink composition may be more dry, which may cause clogging of the nozzles of the inkjet recording head. When the boiling point at 1 atm is higher than 230 ° C., the drying property of the ink composition is lowered, and in particular, the aggregation unevenness of the printed image recorded on the non-ink-absorbing recording medium is conspicuous, and the fixing property of the image. May decrease.

  Specific examples of the alcohol solvent having a boiling point within the range of 180 to 230 ° C. under 1 atm include propylene glycol [188 ° C.], 1,3-propanediol [210 ° C.], 1,2-butanediol [ 194 ° C], 1,3-butanediol [208 ° C], 1,4-butanediol [230 ° C], 1,2-pentanediol [210 ° C], 3-methyl-1,3-butanediol [203 ° C] ], 2-ethyl-2-methyl-1,3-propanediol [226 ° C.], 2-methyl-1,3-propanediol [214 ° C.], 2-methyl-2-propyl-1,3-propanediol [230 ° C], 2,2-dimethyl-1,3-propanediol [210 ° C], 2-methylpentane-2,4-diol [197 ° C], dipropylene glycol [230 ° C], , 2-heptane diol [227 ° C.] and the like. In addition, the numerical value in a parenthesis represents the boiling point under 1 atmosphere.

  The content of the alcohol solvent is based on the total amount of the ink composition from the viewpoint of improving the wettability and penetrability to the recording medium and reducing the unevenness of aggregation, and ensuring the ink storage stability and the ejection reliability. On the other hand, it is preferably contained in the range of 5% by mass or more and 30% by mass or less. When the content of the alcohol solvent is less than 5% by mass, the storage stability of the ink composition is lowered, and the drying property of the ink composition is increased, so that the nozzle of the inkjet recording head is clogged. There is a case. On the other hand, when the content of the alcohol solvent is larger than 30% by mass, the drying property of the ink composition is lowered, and the density unevenness of the printed image recorded on the non-ink-absorbing recording medium is noticeable. Fixability may be reduced. Moreover, it becomes difficult to adjust the viscosity of the ink composition to a range suitable for the ink jet recording method.

  Moreover, when the reaction liquid contains polyhydric alcohols having a boiling point of 280 ° C. or higher, the content of polyhydric alcohols having a boiling point of 280 ° C. or higher is preferably 2.0% by mass with respect to the total amount of the reaction liquid. It is below, More preferably, it is 0-2.0 mass%, More preferably, it is 0-1.0 mass%. When the content of the polyhydric alcohol having a boiling point of 280 ° C. or higher is 2.0% by mass or less, the drying property of the reaction solution tends to be further improved. In the medium, uneven aggregation of the image can be suppressed, and further, the fixability of the image is excellent. Although it does not specifically limit as polyhydric alcohols whose boiling point is 280 degreeC or more, For example, glycerol [290 degreeC] is mentioned.

  The total content of the organic solvent is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, and further preferably 5 to 30% by mass with respect to the total amount of the reaction solution.

(Surfactant)
The reaction solution preferably contains a surfactant other than the betaine compound (amphoteric surfactant). Such a surfactant is not particularly limited, and examples thereof include acetylene glycol surfactants, fluorine surfactants, and silicone surfactants.

  The acetylene glycol-based surfactant is not particularly limited, and examples thereof include 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5- Selected from alkylene oxide adducts of decyne-4,7-diol and alkylene oxide adducts of 2,4-dimethyl-5-decyn-4-ol and 2,4-dimethyl-5-decyn-4-ol One or more are preferred. Although it does not specifically limit as a commercial item of acetylene glycol-type surfactant, For example, E series (A product made by Air Products Japan (Inc)) (Surfinol 465), such as Olfine 104 series and Olfine E1010, Surfynol 61 (trade name, manufactured by Nissin Chemical Industry CO., Ltd.) and the like. One acetylene glycol surfactant may be used alone, or two or more acetylene glycol surfactants may be used in combination.

  The fluorosurfactant is not particularly limited. For example, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, perfluoroalkyl betaine, A fluoroalkylamine oxide compound is mentioned. Although it does not specifically limit as a commercial item of a fluorochemical surfactant, For example, S-144, S-145 (Asahi Glass Co., Ltd. product); FC-170C, FC-430, Fluorard-FC4430 (Sumitomo 3M Co., Ltd. product) FSO, FSO-100, FSN, FSN-100, FS-300 (manufactured by Dupont); FT-250, 251 (manufactured by Neos Co., Ltd.) and the like. A fluorine-type surfactant may be used individually by 1 type, and may use 2 or more types together.

  Examples of silicone surfactants include polysiloxane compounds and polyether-modified organosiloxanes. Although it does not specifically limit as a commercial item of a silicone type surfactant, Specifically, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-347, BYK -348, BYK-349 (above trade name, manufactured by Big Chemie Japan Co., Ltd.), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640 , KF-642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. A silicone type surfactant may be used individually by 1 type and may use 2 or more types together.

  The content of the surfactant is preferably 0.050 to 2.5% by mass and more preferably 0.10 to 2.0% by mass with respect to the total amount of the reaction solution. When the content of the surfactant is within the above range, the wettability of the reaction liquid adhering to the recording medium is further improved, and the aggregation of images tends to be suppressed.

[Ink composition]
The ink composition used in the present embodiment is not particularly limited, but may contain a coloring material, a dispersant, a resin, an organic solvent, a surfactant, and a betaine compound having a molecular weight of 100 to 200.

  Known components can be used as the colorant, dispersant, resin, organic solvent, and surfactant. Moreover, it does not specifically limit as a betaine compound whose molecular weight is 100-200, For example, the same thing as what was described with the reaction liquid can be mentioned. The betaine compounds contained in the ink composition and the reaction liquid may be the same or different. By using the reaction liquid of this embodiment in combination with an ink composition containing a betaine compound having a molecular weight of 100 to 200, the curl suppressing effect of the printed matter tends to be further improved.

[Recording medium]
The recording medium that can be used in the present embodiment is not particularly limited, and examples thereof include an absorptive recording medium, a low-absorbing recording medium, and a non-absorbing recording medium. An ink composition used for a recording method in which the recording medium is an absorptive recording medium is preferred, and further, used in a recording method in which the recording medium is an absorptive recording medium, and a low-absorbency recording medium or a non-absorbing recording medium The ink composition used also for the recording method which is a recording medium is more preferable.

  By using an absorbent recording medium as the recording medium, the curl suppression effect tends to be further improved. The absorbent recording medium is not particularly limited. For example, plain paper such as electrophotographic paper having high penetrability of the ink composition, inkjet paper (an ink absorbing layer composed of silica particles or alumina particles, or polyvinyl chloride). Examples include inkjet recording paper having an ink absorbing layer made of a hydrophilic polymer such as alcohol (PVA) or polyvinylpyrrolidone (PVP), and a recording medium having a support made of paper.

The recording medium with low ink absorption or non-absorption refers to a recording medium having a property of not absorbing or hardly absorbing the ink composition. Quantitatively, a non-ink-absorbing or low-absorbing recording medium is “a recording medium having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method. ". This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method". On the other hand, the ink-absorbing recording medium refers to a recording medium that does not correspond to ink non-absorbing property or low absorbing property.

  Examples of non-ink-absorbing recording media include plastic films that do not have an ink absorbing layer, those that are coated with plastic on a substrate such as paper, and those that have a plastic film adhered thereto. It is done. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

  In addition, examples of the low-ink-absorbing recording medium include a recording medium provided with a coating layer for receiving ink on the surface. For example, as the base material is paper, art paper, Examples include printed paper such as coated paper and matte paper. When the substrate is a plastic film, a hydrophilic polymer is coated on the surface of polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc. And those prepared by coating particles such as silica and titanium with a binder.

  In addition to the above recording medium, a non-ink-absorbing or low-absorbing recording medium such as a plate made of a metal such as iron, silver, copper, or aluminum, or glass can also be used.

  A non-ink-absorbing recording medium is more likely to repel the reaction liquid and ink composition than a low-ink-absorbing recording medium. For this reason, if a non-ink-absorbing recording medium is used, the effect obtained by the present invention (an effect of improving the unevenness of image aggregation, etc.) becomes more prominent.

〔Recording method〕
In the recording method of the present embodiment, the reaction liquid is attached to a recording medium to form a first recording area, and the ink composition is attached to at least a part of the first recording area. And an ink composition attaching step for forming a second recording area.

[Reaction solution adhesion process]
The reaction liquid attaching step is a step of forming a first recording area by attaching a reaction liquid containing a flocculant to a recording medium. The aggregating agent has a function of aggregating the coloring material by reacting with the coloring material contained in the ink composition, the resin or the resin dispersant that can be contained in the ink composition. Thereby, it is possible to suppress the occurrence of printing unevenness or the like of the image recorded by the ink composition, and an image having excellent image quality can be obtained.

  The method for attaching the reaction liquid to the recording medium is not particularly limited, and for example, roller coating, spray coating, and ink jet coating can be used. Among these, the reaction liquid is preferably attached to the recording medium by an ink jet method, and the reaction liquid is preferably applied to the recording medium by a one-pass ink jet method. This is more preferable because it tends to be superior by improving dot landing accuracy and shortening the printing time.

  In the reaction liquid attaching step, the reaction liquid can be discharged from the nozzles of the line head or the serial head and attached onto the recording medium by an ink jet method. In the line method using a line head, the head is fixed and the recording medium is moved along the sub-scanning direction (the longitudinal direction of the recording medium, the conveyance direction), and the nozzle opening of the head is interlocked with this movement. By discharging the reaction droplets, the first recording area can be formed on the recording medium. In the serial method using a serial head, the head is moved along the main scanning direction (the horizontal direction and the width direction of the recording medium), and reaction droplets are ejected from the nozzle openings of the head in conjunction with this movement. Thus, the first recording area can be formed on the recording medium.

The adhesion amount of the flocculant in the reaction solution is preferably 0.01 g / m ² or more and 2.0 g / m ² or less, more preferably 0.02 g / m ² or more and 1.6 g / m ² or less. . By being 0.01 g / m ² or more, the color material and the resin component are more easily aggregated. Moreover, since it is 2.0 g / m < ² > or less, since the drying time of a reaction liquid can be shortened, recording speed-up can be achieved.

Furthermore, the adhesion amount of the flocculant in the reaction solution is more preferably 0.03 g / m ² or more in that the aggregation of the coloring material and the resin component is further excellent. In addition, the reaction solution has a longer drying time while ensuring the effect of aggregating the colorant and resin components, and the amount of the coagulant adhering to the reaction solution is reduced in terms of stickiness of the recorded matter and reduction of odor caused by the flocculant. more preferably from 1.0 g / m ² or less, more preferably 0.5 g / m ² or less, particularly preferably 0.2 g / m ² or less, 0.1 g / m ² or less is more preferable.

  The amount of the coagulant adhering to the reaction liquid is in a region on the recording medium where the surface modification step and the ink composition attachment step are performed. In particular, by performing the above-described surface modification step, it is possible to improve the aggregation of the coloring material and the resin component even when the adhesion amount in the reaction liquid deposition step is set to the above adhesion amount.

  In addition, in the case of having a plurality of adhesion regions in which the adhesion amount of the flocculant is different in the reaction liquid adhesion step, it is preferable that it is in the region where the adhesion amount of the flocculant is the largest in terms of the above points being more excellent. .

  A step of drying the reaction solution may be provided after the reaction solution attaching step and before the ink composition attaching step. In this case, it is preferable to perform drying to such an extent that no stickiness is felt when the reaction liquid adhering to the recording medium is touched. The drying step of the reaction solution may be performed by natural drying, but may be drying accompanied by heating from the same viewpoint as described in the case of drying the resin solution. The method for heating the reaction liquid is not particularly limited, but the same methods as those mentioned in the method for heating the resin liquid can be used.

  Furthermore, a surface modification step of the recording medium may be included before the reaction liquid attaching step. The surface modification step is a step of performing surface modification of the recording surface of a recording medium with low or non-absorbing ink so that the wetting tension index of the recording surface is 40 mN / m or more. Thereby, since the wettability of the reaction liquid can be improved, the reaction liquid can be uniformly attached on the recording medium. The “wetting tension index” in the present invention refers to a wetting tension measured according to “Plastic-film and sheet-wetting tension test method (JIS K6768: 1999)”.

  For the surface modification of the recording surface in the surface modification step, any processing method may be used as long as the wetting tension index of the recording surface can be 40 mN / m or more, for example, corona treatment, atmospheric pressure plasma treatment, flame Treatment, ultraviolet irradiation treatment, solvent treatment, resin liquid adhesion treatment (for example, primer treatment), and the like. These treatment methods can be carried out using a known apparatus.

[Ink composition adhesion process]
The ink composition attaching step is a step of forming the second recording region by attaching the ink composition to at least a part of the first recording region after the reaction liquid attaching step described above. As a result, the color material contained in the ink composition reacts with the aggregating agent so that the color material aggregates on the recording surface, so that the color developability of the recorded image can be improved. Further, since the ink composition adheres to the recording surface on which the reaction liquid is uniformly applied, the reaction with the flocculant is uniformly performed regardless of the position where the ink composition is attached. Thereby, generation | occurrence | production of the printing nonuniformity etc. of the image recorded can be suppressed favorably.

  In the ink composition attaching step, the ink composition can be ejected from the nozzles of the line head or serial head and attached onto the recording medium by an ink jet method. In the line method using a line head, the head is fixed and the recording medium is moved along the sub-scanning direction (the longitudinal direction of the recording medium, the conveyance direction), and the nozzle opening of the head is interlocked with this movement. By ejecting the ink droplets, the second recording area can be formed on the recording medium. In the serial system using a serial head, the head is moved along the main scanning direction (the horizontal direction and the width direction of the recording medium), and ink droplets are ejected from the nozzle openings of the head in conjunction with this movement. Thus, the second recording area can be formed on the recording medium.

The adhesion amount (as a composition) of the ink composition in the ink composition adhesion step is 0.01 g / m ² or more and 25 g / m ² or less, which is desirable for the recorded material while improving the image quality of the recorded material. preferably in that it can reduce the amount of the color-imparting capable dots or ink composition, the upper limit is, 20 g / m ² or less, still more preferably 15 g / m ² or less, more is 10 g / m ² or less preferable. The amount of adhesion is in the area of the recording medium on which the above-described surface modification process and reaction liquid adhesion process are performed.

By using a reaction solution, image quality can be improved, such as suppressing aggregation unevenness, even in high-speed printing in one-pass printing, but on the other hand, the amount of moisture that has been driven onto the recording medium increases, resulting in more curling. It becomes easy. In this respect, by using the reaction liquid of the present embodiment, it is possible to improve the recording speed while suppressing the occurrence of curling.

  The recording method can be a recording method in which the recording medium is an absorptive recording medium or a recording method in which the recording medium is a low or non-absorbing recording medium. The former is preferred because the present invention is particularly useful. In addition, using a recording apparatus capable of executing the former recording method and the latter recording method, at least one of the recording methods is selected according to the user designation, the type of recording medium, the type of image to be recorded, etc. Thus, a recording method for executing the selected recording method may be used.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Reaction liquid materials]
[Flocculant]
Magnesium sulfate Calcium acetate Polyallylamine (PAA-01, manufactured by Nittobo Medical Co., Ltd., 15% solids)
[Betaine]
Trimethylglycine L-carnitine myristylamidopropylbetaine (molecular weight: 357)
[Surfactant]
BYK348 (silicone surfactant, manufactured by BASF)
[Organic solvent]
Propylene glycol (boiling point: 189 ° C)
Glycerin (boiling point: 290 ° C)
N-methyl-2-pyrrolidone

[Material of ink composition]
[Color material]
C. I. Pigment Blue 15: 3
(Resin dispersant)
Styrene-acrylic acid copolymer (weight average molecular weight 25000, Tg: 80 ° C., oxidation 180)
[Resin emulsion]
Styrene-acrylic acid copolymer (weight average molecular weight 50000, Tg: 80 ° C., oxidation 130, average particle diameter 75 nm)
[Surfactant]
BYK348 (silicone surfactant, manufactured by BASF)
Surfynol DF110D (acetylene glycol surfactant, manufactured by Nissin Chemical Industry Co., Ltd.)
[Organic solvent]
1,2-hexanediol 2-pyrrolidone propylene glycol trimethylglycine

[Preparation of reaction liquid and ink composition]
Each material was mixed with the composition shown in the following Tables 1 and 2, and stirred sufficiently to obtain each reaction solution and each ink composition. In Tables 1 and 2 below, the unit of numerical values is% by mass, and the total is 100.0% by mass.

〔Recording method〕
The reaction liquid was applied to the following three types of recording media using a bar coater so as to have a coating amount (liquid mass) of 5.5 g / m ² to form a first recording area (reaction). Liquid adhesion process). After application of the reaction solution, the recording medium was heated at 40 ° C. and it was confirmed that there was no stickiness by finger touch. The remaining volatilization amount of the reaction liquid in the recording medium at the time of the ink composition attaching step described later was about 10% by mass in each example. The remaining volatilization rate was obtained by measuring the mass of the recording medium.
(Recording medium)
Plain paper (trade name “Xerox4200” manufactured by Xerox, A4 size)
Printed paper (trade name “OK Top Coat N” manufactured by Oji Paper Co., Ltd., A4 size)
Film (trade name “SY51M”, polypropylene film manufactured by UPM RAFLATA, A4 size)

  Thereafter, each recording medium was fed to a printer, and with the surface temperature of the recording medium heated to 40 ° C., the ink composition 1 was adhered to the first recording area to obtain each recorded matter ( Ink composition adhesion step). In the ink composition attaching step, a solid image having an image resolution of 600 × 600 dpi was formed with a weight of 18 ng per drop (pixel) of the ink composition. Further, the reaction liquid and the ink composition were adhered to the entire recording area as a recording area except that a margin of 1 cm was left around the recording medium.

  As the printer, an ink jet printer PX-M7050F (trade name, manufactured by Seiko Epson Corporation, nozzle resolution: 600 dpi) was remodeled by attaching a platen heater, and the ink cartridge filled with the ink composition was used.

[Solid uniformity]
After the ink composition attaching step, the obtained recorded matter was dried by heating at 70 ° C. for 2 minutes. The solid pattern agglomeration unevenness of the recorded matter obtained using plain paper as the recording medium was visually confirmed, and the solid uniformity was evaluated based on the following evaluation criteria.
(Evaluation criteria)
○: No aggregation unevenness Δ: Some aggregation unevenness can be confirmed ×: Printing unevenness accompanied by repelling of the ink composition can be confirmed

[Curl properties]
After the ink composition attaching step, the obtained recorded matter was left in an environment at 25 ° C. for 24 hours.
Two types of recorded matter were prepared using ink compositions 1 and 2. The curl amount at the four corners of the recorded matter obtained using plain paper as the recording medium was measured, and the average amount was calculated. Based on the average value obtained, the curl property was evaluated based on the following evaluation criteria.
(Evaluation criteria)
◎: Less than 1.0 cm ○: 1.0 cm or more and less than 5.0 cm ×: 5.0 cm or more

[Fixability]
After the ink composition attaching step, the obtained recorded matter was left in an environment of 25 ° C. for 5 hours. A second recorded area of a recorded matter obtained using a printing paper as a recording medium and a recorded matter obtained using a film as the recording medium was subjected to a Gakushin type friction fastness tester (product name “AB- 301 "(manufactured by Tester Sangyo Co., Ltd.) was rubbed with a cotton cloth under a load of 200 g. Thereafter, the peeled state of the recording surface and the ink transfer state to the cotton cloth were visually confirmed, and the fixing property was evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: Ink peeling and ink transfer to cotton cloth were not observed even after rubbing 30 times.
○: Ink peeling and ink transfer to cotton cloth were not observed even after rubbing 10 times, but ink peeling or ink transfer to cotton cloth was recognized after rubbing 30 times.
Δ: Ink peeling or ink transfer to cotton cloth was observed after rubbing 10 times.
X: Ink peeling or ink transfer to cotton cloth was observed before rubbing 10 times.

[Head clogging recovery (long-term clogging recovery)]
The reaction liquid was filled in the head of an ink jet printer (product name “PX-G930”, manufactured by Seiko Epson Corporation, 180 nozzles) which is an ink jet recording type printer. After filling, a discharge inspection was performed to confirm that there was no nozzle clogging (initial check). Then, the cap of the printer head was removed (that is, the head nozzle surface was easy to dry), and it was left in an environment of 25 ° C./40-60% RH for one week. After leaving, the head was covered with a suction cap and sucked to perform a cleaning operation for discharging 5 cc of the reaction liquid from the head. A nozzle discharge inspection after cleaning was performed, and the long-term clogging of the inkjet head of the reaction liquid was evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: ○: Reaction liquid was normally discharged from all nozzles within 4 cleaning operations.
B: x: In the cleaning operation four times, there were nozzles that did not normally discharge the reaction liquid.

[Short-term clogging recovery]
In the above long-term clogging recoverability, after the initial confirmation, the reaction liquid was continuously discharged from all nozzles of the head for 3 minutes at a discharge frequency of 10 kHz. After the end of continuous discharge, the cap was removed and left for 1 minute. After being allowed to stand, as a flushing for discharging the thickened reaction liquid from the nozzle, continuous discharge was performed for 3 seconds at a discharge frequency of 10 kHz, and then a nozzle discharge test was performed. As a set, after the inspection, the nozzles were cleaned to confirm that there was no nozzle clogging, and then continuous ejection was performed again. This was repeated 5 times in total, and the short-term clogging property of the ink jet head of the reaction liquid was evaluated based on the following evaluation criteria.
(Evaluation criteria)
A: The number of non-ejection nozzles was 2 or less in all five inspections.
B: There were at least one inspection in which the number of non-ejection nozzles was 3 or more.

  Since Comparative Example 1 did not contain a flocculant, it was found that the uniformity and the fixability were inferior. Moreover, since the comparative example 2 did not contain a betaine compound, it turned out that it is inferior to curl property. Furthermore, since Comparative Example 3 did not contain a betaine compound, the curling property was inferior, and since the organic solvent having a boiling point of 290 ° C. was included, the fixability to the film was also lowered. Moreover, the comparative example 4 became a reaction liquid with a high viscosity by containing a betaine compound with a molecular weight exceeding 200. Therefore, nozzles are likely to be clogged due to bubbles entering the head at the time of ejection, and the clogging recovery performance in the long term and short term is poor. Moreover, it is considered that the high-viscosity reaction liquid tends to thicken by drying, and clogging is caused by the high viscosity of the reaction liquid. In particular, in terms of short-term clogging recovery, it has been shown that the increase in nozzle viscosity during head pause is not recovered by flushing.

  In addition, in the application other than the ink jet method such as roller application or bar coater application, when the reaction liquid has a high viscosity, the workability of the application is lowered. Further, when one-pass recording was performed using the reaction liquid and ink of Example 1 using a line printer having an inkjet head having the width of the recording medium, the same effect as described above was obtained.

Claims (12)

Water, a flocculant for aggregating the components of the ink composition, and a betaine compound having a molecular weight of 100 to 200,
In the recording method in which the ink composition is attached to a recording medium by an ink jet method, the recording medium is used by being attached to the recording medium.
Reaction liquid.   The reaction solution according to claim 1, wherein the content of the betaine compound is 2.0 to 20% by mass.   The reaction solution according to claim 1 or 2, wherein the betaine compound contains a betaine compound having a trimethylamino group.   The reaction solution according to any one of claims 1 to 3, wherein the flocculant contains at least one selected from the group consisting of a polyvalent metal salt, an organic acid, an organic acid salt, and a cationic polymer. Including polyhydric alcohols having a boiling point of 280 ° C. or higher,
The reaction solution according to any one of claims 1 to 4, wherein the content of the polyhydric alcohol is 2.0% by mass or less.   The reaction liquid according to claim 1, which is used in the recording method in which the recording medium is an absorbent recording medium.   Furthermore, the reaction liquid according to claim 6, which is also used in the recording method in which the recording medium is a low-absorbency recording medium or a non-absorbing recording medium.   The reaction liquid according to claim 1, wherein the ink composition contains a betaine compound having a molecular weight of 100 to 200.   The reaction liquid according to claim 1, which is attached to the recording medium by an inkjet method.   The inkjet head having a nozzle for discharging the reaction liquid is attached to the recording medium by an inkjet method while being scanned relatively once with respect to the recording medium. The reaction solution according to any one of the above. The adhered amount of the medium to be recorded of the flocculant is a 0.010~2.0g / m ^2, the reaction solution according to any one of claims 1 to 10. A reaction liquid attachment step of attaching the reaction liquid according to any one of claims 1 to 11 to the recording medium to form a first recording area;
An ink composition attaching step of attaching an ink composition to at least a part of the first recording area to form a second recording area,
Recording method.